/*
 *  simple.c
 *  This program draws a white rectangle on a black background.
 */


#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>         /* glut.h includes gl.h and glu.h*/
#endif

void display(void)
{
    /* clear window */

    glClear(GL_COLOR_BUFFER_BIT); 


    /* draw unit square polygon */

    glBegin(GL_POLYGON);
        glVertex2f(-0.5, -0.5);
        glVertex2f(-0.5, 0.5);
        glVertex2f(0.5, 0.5);
        glVertex2f(0.5, -0.5);
    glEnd();

    /* flush GL buffers */

    glFlush(); 

}


void init()
{

    /* set clear color to black */

    /* 	glClearColor (0.0, 0.0, 0.0, 0.0); */
    /* set fill  color to white */

    /* 	glColor3f(1.0, 1.0, 1.0); */

    /* set up standard orthogonal view with clipping */
    /* box as cube of side 2 centered at origin */
    /* This is default view and these statement could be removed */

    /* glMatrixMode (GL_PROJECTION);
       glLoadIdentity ();
       glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);  */
}

int main(int argc, char** argv)
{

    /* Initialize mode and open a window in upper left corner of screen */
    /* Window title is name of program (arg[0]) */

    glutInit(&argc,argv); 
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);  
    glutInitWindowSize(500,500);
    glutInitWindowPosition(0,0); 
    glutCreateWindow("simple"); 
    glutDisplayFunc(display);
    init();
    glutMainLoop();

}
